Adjustable-shut-height press



Aug. 28, 1962 J. WEBSTER 3,051,078

ADJUSTABLE-SHUT-HEIGHT PRESS Filed Aug. 9, 1960 5 Sheets-Sheet 1 INVENTOR JOHN L WEBSTER BY M 9 ATTORNEY Aug. 28, 196 J. L. WEBSTER ADJUSTABLE-SHUT-HEIGHT PRESS Filed Aug; 9, 1960 5 Sheets-Sheet 2 INVENTOR JOHN L. WEBSTER ATTORNEY g- 28, 1952 J. L. WEBSTER 3,051,078

- ADJUSTABLE-SHUT-HEIGHT PRESS INVENTOR JOHN L. WEBSTER BY 4 l ATTORNEY g- 1962 J. L. WEBSTER 3,051,078

ADJUSTABLE-SX-HJT-HEIGHT PRESS Filed Aug. 9, 1960 5 Sheets-Sheet 4 v E 3 g I *2 8 3" 3Ag: R

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ATTORNEY Aug. 28, 1962 J. WEBSTER 3,051,078

ADJUSTABLE-SHUT-HEIGHT PRESS Filed Aug. 9, 1960 5 Sheets-Sheet 5 rNvENTok JOHN L. WEBSTER BY 4w & 9W

ATTORNEY United States Patent Office 3,dl,078 Patented 23, 1962 3,051,078 ADJUSTABLE-SHUT-HEIGHT PRESS John L. Webster, Henrico County, Va, assignor to Reynolds Metals Company, Richmond, Va, a corporation of Delaware Filed Aug. 9, 1960, Ser. No. 48,544 14 Claims. ((Il. 190-257) This invention relates to presses and, in particular, to presses operated by mechanical linkages.

One object of the invention is to provide an improved press having a wide range of shut-heights and in which an adjustment from one shut-height to another may be made rapidly and with a small expenditure of labor.

Another object is to provide a press capable of exerting heavy pressures by means of mechanical leverages.

A further object is to provide a compact, relatively light-weight and relatively inexpensive press capable of exerting heavy pressure upon a work piece.

A still further object is to provide a press having a movable upper platen actuated by levers and maintaining a parallel relationship to its companion lower platen during its movement.

Other objects and advantages of the invention will become more apparent as the description proceeds and when considered in conjunction with the accompanying drawings in which:

FIG. 1 is a side elevation view of the press with the platens in contact with each other and with portions of the structure broken away.

FIG. 2 is an end elevation of the press of FIG. 1;

FIG. 3 is a top plan View of the press of FIG. 1;

FIG. 4 is a diagrammatic view showing a suitable hydraulic system for use with the press of FIG. 1 and including conventional J.I.C. hydraulic symbols;

FIG. 5 is a sectional view of a detail taken on line 55 of FIG. 2;

FIG. 6 is a sectional view of a detail taken on line 6--6 of FIG. 2;

FIG. 7 is a sectional view of a detail taken on line 77 of FIG. 3;

FIG. 8 is a sectional view of a detail taken on line 88 of FIG. 2, and

FIG. 9 is a sectional view of a detail taken on line 9-9 of FIG. 2.

In accordance with the invention a press having an adjustable shut height is provided with a frame and platens, the upper platen being movable toward and away from the lower platen while remaining parallel thereto and being actuated by power cylinders located to one side of the frame through the intermediary of a series of levers extending transversely of the platens. Lifting cylinders also are provided for raising and holding the upper platen incident to an adjustment of the press shut height, and these cylinders further assist in maintaining the upper platen parallel to the lower platen during the normal operations of the power cylinders. The frame is comprised of an assembly of relatively light-weight structural elements arranged in combination with the respective cylinders to provide for a given press tonnage capacity, a more compact, less expensive and lighter-weight press than conventional presses of this type having equal tonnage capacities.

Referring now to FIGS. 1, 2 and 3, the press includes a framework having a number of elongated, parallel spaced, base plate members 10, '11, 12, 13 and 14, mounted on edge upon any suitable supporting surface 15. Talring a base plate 14 at one end of the frame as an example, this base plate at its rearward edge, corresponding to one side of the press, is confined between and rigidly secured to two elongated upright members 16 and 17.

Also attached to a side surface of this base plate at an as the previously described upright members.

' cured at its ends by nuts, as best seen in FIG. 1.

intermediate location between its ends is another upright member 18, the space above the base member and between uprights 16, 17 and upright 18 serving to enclose a stationary lower platen 20 and a movable upper platen 21, later to be described. As the uppermost ends of upright members 16 and 17, a pair of parellel elongated brace members 22 and 23 spaced from each other and extending transversely of the platens are rigidly afiixed to those uprights, these brace members being attached also to corner braces 24 and 25 which in turn are rigidly attached to the sides of the upright member 18 at its upper end. Similarly, the base plate 10 at the other end of the frame is likewise mounted and braced against similar uprights, including upright 18a a similar pair of elongated brace members 26 and 27 spaced from each other, being employed in the combination. Thus, at the two extreme ends of the press and at the highest part of the press frame, the pairs of transverse brace members provide a convenient mounting for the lifting cylinders, later to be described.

The centrally located base plates 11, 12 and 13 are each rigidly attached to and confined at their rearward ends between pairs of upright members 30, 31; 32, 3-3; and 34, 35, respectively, these uprights not being as long At their upper ends these shorter uprights are each rigidly attached to a side brace 36 extending across the entire side of the frame and affixed also to the earlier described longer uprights, as best seen in FIG. 3. Further bracing of the frame is secured by means of an elongated tie rod 37 extending through apertures in each of the base plates adjacent the forward end thereof, suitable tubular spacers 33, 391, 40 and 41 surrounding that tie rod being disposed between adjacent base plates, and with the rod being se- Other tie rods, such as seen at 42 and 43, arranged in the same manner, may be employed as desired. As will thus be apparent, a compact well braced and relatively light-Weight press frame is provided for the press operation later to be described.

As a significant feature, the invention makes possible a ready adjustment of shut height for the press and in this respect each of the rear upright members is provided with a plurality of vertically arranged apertures therethrough as seen at 44 in FIG. 2. For each pair of rear uprights a fulcrum member is adjustably mounted therebetween and includes a forwardly projecting portion 45. As seen in FIG. 5, the pairs of uprights 34, 35 and 16, 17, for example, may have fulcrum members 46 and 47, respectively, the fulcrum member 46 also appearing on FIG. 3. These fulcrum members aresecurely fastened to the respective uprights by means of suitable pins 48 and 49 extending through the selected apertures 44, and the forwardly projecting portions 45 of each fulcrum member in turn has an aperture therethrough for mounting of a pivoted lever next to be described. The pins which are removable from the uprights and fulcrum members during an adjustment of the shut height of the press, may conveniently be held against axial movement by means of readily removable retaining rings 50 at each end thereof. Rather than employing long pins, it is preferred to use shorter ones extending through less than all of the fulcrum members. As will be understood, similar mountings are employed for the fulcrum members associated with the pairs of rear uprights other than those seen in FIG. 5.

Referring now to FIGS. 2 and 6, the forward end 45 of each fulcrum member pivotally supports the rearward ends of a pair of elongated lever arms, such as shown at 51 and 52, associated with power cylinder 53. By means of a short pin 54 extending through apertures in the lever arms and fulcrum member, these arms may pivot about for fastening purposes.

the pin 54 as a fulcrum. The pin, moreover, is restrained against axial movement by retaining rings 55 at each end thereof. The remaining piars of lever arms 56, 57; 58, 59; 60, 61 and 62, 63, associated respectively with power cylinders 64, 65, 66 and 67 and with the other fulcrum members, are similarly mounted for pivotal movement at their rearward ends.

Passing now to FIG. 7, the upper surface of movable platen 21 has rigidly affixed thereto, as by bolts 68, a pair of spaced brackets 69 and 70 between which is pivotally mounted a link 71 by means of a pin 72 passing through apertures in the brackets and in the link, the pin being held against axial movement by a retaining ring 73 at each end. The upper end of the same link is pivotally mounted by means of a pin 74 between the pair of lever arms 56 and S7 and with the 'pin 74 being restrained against axial movement by the retaining rings 9, each of the axes of the pins 72 and 74 preferably lying in a common vertical plane when the platens are in contact with each other and with that vertical plane being forwardly of the axis of pin 54. Thus, as the lever arms are pivoted upwardly or downwardly during operation of the press, they serve to move the upper platen with them through the connection afforded by the described link. It will be understood that similar links 75 and 76 are provided for the other pairs of centrally disposed lever arms 58, 59; and 60, 61, but that a diflferent link, now to be described, is provided for the endmost pairs of lever arms. Also, the location of all of the brackets connecting these links to the upper platen is generally along the longitudinal center line of that platen.

Referring now to FIG. 8, the upper surface of platen 21 has rigidly afiixed thereto, as by bolts 68, a pair of spaced brackets 79 and 80, similar to the described brackets 69 and 70, and between which is pivotally mounted a link 81 somewhat longer than the described link 71. Link 81 is pivotally mounted to its brackets by means of a pin 82 passing through apertures in the pin and brackets, the pin being held against axial movement by a retaining ring 83 at each end. The upper end of the link is provided with a recess into which the lower end of the connection 84 of the lifting cylinder piston rod extends, being pivotally engaged therewith by means of a bolt 85 having a nut 86 In addition, the link 81 is pivotally engaged by means of a pin 74a as above described and passing through apertures in that link and in the lever arms 51 and 52, the pin 74a being restrained against axial movement by the retaining rings 8. A similar linkage is employed with platen 21, lever arms 62, 63, link 81a, and the piston rod of lifting cylinder 91, at the opposite end -of the press.

Each of the lifting cylinders 90 and 91 which, for example, when employing pressure fluid at about 2000 psi, may be about 5 inches in inner diameter with a 24 inch tion about shafts 92 and 93 fastened in the cylinder walls -and extending into recesses in the brace members. These cylinders are preferably of the double-rod-end type with a continuous piston rod extending through both of the cylinder heads and attached to a piston 94 within the cylinder and extending through packing glands 95. Fluid displacement on both sides of the respective pistons in the respective cylinders is so coordinated that the piston rod extensions 84 move simultaneously and enable the lifting cylinders to maintain the parallelism of the two platens at all times. As shown at 149 and 151 for cylinder 90 in FIG. 1, suitable flexible supply conduits are attached to the respective ends of the cylinders to supply and withdraw the pressure fluid, similar connections being provided for the companion cylinder 91, as will later be apparent.

Referring now to FIG. 9, the forward ends of the lever arms 51 and 52 embrace therebetween a piston rod extension 98 which is connected to the piston of power cylinder 53, the extension being pivotally aflixed to those lever arms as by means of a pin 99 retained against axial movement by retaining rings 1% at each end. As in the case of the shiftable fulcrum members, the piston rod extension 98 is provided with a series of vertically spaced apertures 101 through one of which the pin 99 is detachably arranged. The extreme forward ends of the lever arms may also be provided with a cap 102 bolted thereto, as when the aperture for the pin 99 extends to the outermost end of those levers for simplicity in assembling the structure during a change in the shut height of the press. In similar manner, each of the other pairs of lever arms are pivotally engaged with the piston rod extensions from the pistons of the other power cylinders.

Each of the power cylinders, as seen in FIGS. 1 and 2, may, when employing a pressure fluid at about 2000 psi. with a press tonnage capacity of about 2000 tons, be about 10 inches in inner diameter and with a stroke of about 15 inches. These cylinders are pivotally secured at their lower ends as by a pin 103 passing through each base plate member adjacent the forward end-s of those members and through a pair of depending bosses 104 and 105 aflixed :to the lower end of the cylinder. As indicated in FIG. 1, suitable headers 106 and 107 have flexible conduits .108 and 189 attached thereto leading to the respective ends of the power cylinders to supply and withdraw the pressure fluid therefor.

As seen in FIG. 2 the lower platen 20 rests upon elongated stringers M0 and 111 extending across the tops of the base plate members from end to end of the frame, such stringers being attached both to the lower surface of that platen and to the top of those base plate members. Preferably, the rear side of the platen rests in contact with the confronting edges of the rearward uprights and the rear side of the upper platen also preferably moves in contact with those edges of the uprights serving as a guide for the upper platen. Near each end of the upper platen a pair of recesses are formed in the front side thereof in confronting relation to the inner edges of the forward uprights 18 and 18a and within these recesses a pair of compression springs are disposed acting to project outwardly a pair of upper-platen-stabi li2ing pins 112 and 113.

It will be appreciated that the press thus far described may be employed for many usages upon confinement of a work piece between the platens. Such platens may have smooth confronting surfaces or may support dies, or the like. In one usage, the press may be employed in the expansion of a hollow passageway panel as indicated diagrammatically in FIG. 4. Such a panel may comprise a composite flat sheet of aluminum having two originally separate laminations bonded together in certaln regions defining the boundaries of the passageway as seen in dot-ted lines. The passageway has an unbonded entranceway 121 and an unbonded outlet 122 into which expansion nozzles 123 and 1124 may be inserted. Upon application of a high pressure inflating fluid to the unbonded portions of the panel while confined between the platens of the described press, the appropriate portions of the panel are stretched and form the desired passageways. When the present press is to be employed for such a use it will be understood that a separate pressure fluid system will normally be employed to effect the panel expansion and such a system, forming no part of the present invention, may conventional-1y comprise a separate reservoir 125 containing a substantially incompressible liquid and from which a heavy duty pump 126, driven by a motor 127, draws the liquid through conduit 123. The pump discharges into a conduit 129 equipped with a control valve 130 and connected at its end to the nozzle 124 adapted to be fitted in pressure tight relation to the unbonded passageway inlet to the panel. The unbonded outlet passageway of the panel likewise may be connected in fluid tight relation with nozzle 123 in a return conduit i131 controlled by valve 132.

For the purpose of operating the piston-and-cylinder assemblies of the press, however, a variable discharge pump 140 driven by motor 141 draws from a supply reservoir 139 and discharges into header 14-2 having a relief valve 143 and a manually operable three-way selector valve 144 connected thereto. From selector valve 144 fluid under pressure may be directed from header 142 into conduit 14-5 leading to a manually operable, open center, four-way selector valve 146. Leading from valve 146 are headers 106 and 107 serving respectively to supply pressure fluid to, and vent pressure fluid from the upper ends of the power cylinders and the lower ends of the power cylinders depending upon the settings of valves 146 and 144. From selector valve 144 pressure fluid may also be directed into conduit 147 leading to another open center, four-way manually operable selector valve 148. Leading from Valve 143 are conduits 149 and 156 which connect respectively with the lower end of lifting cylinder 90 and the upper end of lifting cylinder 91. In addition, a transfer conduit 151 connects the lower end of cylinder 91 and the upper end of cylinder 94 and a norrnally closed bypass conduit 1'52. controlled by a manually operable valve 153 connects conduits 15d and 151. Suitable vents for each of valves 143, 146 and 148 and leading into the reservoir 139 also are provided, and conventional valves and pumps are employed.

Having thus described a suitable combination of structure and allied hydraulic system for carrying out the invention, the novel features and capabilities of the invention will now be apparent to those skilled in the art upon considering the following operation of the structure. Assuming that a thin work piece, such as the panel 129 is to be worked upon and with the press platens in contact with each other, as seen in FIGS. 1 to 3, the operator adjusts valve 145 to direct pressure fluid into header 107 thus raising the extensions 98 associated with the rising pistons in each of the power cylinders, the fluid above those pistons now venting through valve 145. As these extensions rise, the pairs of lever arms pivoted thereto by pins 99 pivot about the rearward pins 54 as a fulcrum. Moreover, the respective links 81, 71, 75, 76 and 81a connected between the upper platen and those rising lever arms likewise lift the upper platen and provide a space into which the panel may be inserted between the platens. It will be noted that in this rising movement the rear side edge of platen Z1 rides in contact with the edges of the rear uprights and that the heavy compression springs behind the stabilizing pins 112 and 113 cause such rear edge of the platen to maintain that contact. During this rising movement the upper ends of both links 81 and 81a are displaced slightly forward, pivoting about their pins 82, and through the piston rod projections 84 causing each of cylinders 90 and 91 to rock about their points of suspension in the pairs of brace members 22, 23 and 26, 27. Likewise, the power cylinders pivot to a slight extent about their pins1tl3. Thus, as the platen 21 rises, its lower surface remains parallel to the upper surface of the lower platen and, of significance, no transverse shifting of the upper platen with respect to the lower platen occurs. Moreover, as piston rod projections 84 are actuated by the rising of the platen, they force their connected pistons slightly upward in the lifting cylinders, displaced fluid above the piston in cylinder 90 passing to cylinder 91 below the piston therein and displaced fluid above the piston in cylinder 91 passing to the open center of valve 143 and thence to cylinder 90 below the piston therein, as seen in FIG. 4. In addition, upward movement of the pistons in each of the power cylinders transfers fluid through header 166 into the vent of valve 146.

With the panel 120 in place, the operator then shifts valve 146 to pass pressure fluid from conduit 145 to header 1% thus to move each of the piston rod extensions 98 downwardly in unison and to vent the lower ends of the power cylinders through that valve. As this occurs, the piston rod extensions 98 pull each of the pairs of lever arms downwardly about their pins 54 as a fulcrum and with a magnified leverage commensurate with the respective distances between pins 54 and 99 and between pins 54 and 74 or 74a. This leverage in turn is transmitted through the links to the upper platen and thence to the work piece confined between the platens. In moving downward, moreover, the upper platen remains parallel with the lower platen and with-out partaking of any transverse movement which might abrade the work piece.

Downward movement of the platen also moves the piston rod projections 84 downwardly with a rocking movement of the cylinders and 91 opposite to that previously described. At this time fluid displaced from beneath the piston in cylinder 90 passes through conduit 149, the open center of valve 148 and conduit 154) to the upper end of cylinder 91, while fluid displaced from beneath the piston in cylinder 91 passes through conduit 151 to the upper end of cylinder 96, this fluid displacement serving to provide synchronous movement of the piston rod projections $4 and thus to maintain parallelism of the platens. it will be further understood that, while the power cylinders are applying pressure to the platens with the lever arms pivoted downwardly, the expansion of the passageway panel by employment of its own pressure system will be conducted. As will be noted, the movement of the upper platen under the action of the power cylinders is also reflected in movement by the pistons in the lifting cylinders and the by-passing of incompressible liquid between those lifting cylinders. Accordingly, the lifting cylinders serve to synchronize the upper platen movement and being attached to the ends of that platen also serve to hold it in parallel relation to the lower platen at all times.

Having thus described a normal press operation with a work piece requiring a small shut-height dimension, the following operation would be conducted if the succeeding work piece were of a size requiring a much greater shut height. The operator accordingly would first detach each of the pairs of levers from their respective piston rod extensions 98, as by removing the several caps 102, pushing each pin 99 endwise sufliciently to clear the aperture 101 of the piston rod extension 98, and then pivoting that extension to the left, .as seen in FIG. 2. The operator next moves each of the longer pins 48 and 49 endwise toward the right-hand end of the press as seen in FIG. 3 until the apertures of the fulcrum members 46 and 47 are uncovered by those pins. Similarly, the companion elongated pins for the three other fulcrum members are moved endwise toward the left-hand end of the press until the apertures of those fulcrum members are uncovered thereby. At this time, the upper platen rests upon the lower platen and the ends of all levers are now detached from the frame. The above-described lever-disconnecting operation may be easily and rapidly carried out by the operator standing on surface 15.

With each of the levers so disconnected, the operator then shifts valve 14 1 to direct pressure fluid into conduit 147 and then shifts valve 148 to direct. this fluid from conduit 147 into conduit 149. As this occurs, fluid is first directed under the piston in lifting cylinder 91) and this piston starts to rise in a controlled manner carrying with it, through the piston rod projection 84, the upper platen, each of the fulcrum members, and each of the pairs of levers. As this lifting movement takes place, the piston in cylinder 91 likewise is lifting the same described parts. Fluid displaced from above the piston in cylinder 90 is transferred under pressure through conduit 151 to below the piston in cylinder 91 and assists in the lifting action. In the meantime, fluid displaced from above the piston in cylinder 91 vents from valve 143 until the desired amount of lifting has been accomplished. At that time, the operator then shifts valve 148 to cut off further supply of fluid to conduit 149 at which time the load supported by the pistons in the two lifting cylinders comes to rest. Normally, a skilled operator can bring the load to rest at an elevation such that the apertures in the fulcrum members will be in alignment with the desired apertures 44 in the uprights corresponding to the shutheight desired for the press. Since an important function of the lifting cylinders is to maintain parallelism of the platens and since a certain amount of leakage may occur in the hydraulic system, the manually adjustable valve 153 serves a significant purpose in this regard. For example, with the valve 153 in open position, the upper platen may be adjusted into parallelism with the lower platen, fluid meanwhile filling the respective ends of the lifting cylinders 90 and $1 and the conduits connected therewith. After such adjustment, the valve 153 is closed and thereafter the synchronous movement of the pistons in those cylinders will again be assured.

When the respective apertures are in alignment at the desired shut-height, the elongated pins are then reinserted into fulcrum members and the uprights and the rear ends of the pairs of levers once more become attached to the frame. Thereafter, the piston rod extensions 98 are pivoted to engage between the forward ends of the levers, the pins 99 are moved endwise to engage in the chosen aperture 101 within those extensions and the caps 102 are restored in place. It will be understood that at this time the upper and lower platens are separated from each other at a shut-height different from the one employed in the expansion of the fiat panel 120 previously described, but that the same magnified leverage upon the work piece Will be exerted when the press is operated.

After thus changing the shut-height, the operator then moves valve 144 to direct pressure fluid into conduit 145 and the press is again in operable condition.

Having thus described the invention and having shown a presently preferred embodiment thereof, it will be understood that numerous changes may be made in the construction and mode of operation without departing from the spirit of the invention, and it is, therefore, desired that the present embodiment be considered as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.

What is claimed is:

l. In combination in a press having an adjustable shut height, a frame having a vertically arranged upright at one side thereof, a lower platen, an upper platen movable toward and from said lower platen, a fulcrum member adjustably and removably mounted upon said upright, a power piston-and-cylinder assembly pivotally mounted at the side of said frame opposite said upright and having a power piston rod extending outwardly of said power cylinder, a lever extending across said upper platen and having a first end pivotally attached to said fulcrum merm ber and a second end pivotally and removably attached to said power piston rod, a link pivotally attached at its respective ends to said upper platen and to said lever intermediate the ends of said lever, a lifting piston-andcylinder assembly pivotally mounted upon said frame above said upper platen and having a lifting piston rod projecting downwardly from said lifting cylinder, means pivotally connecting said lifting piston rod to said upper platen, means for directing pressure fluid to and from said power piston-and-cylinder assembly thereby to move said upper platen selectively toward and away from said lower platen, and means for directing pressure fluid to and from said lifting piston-and-cylinder assembly thereby to support said upper platen, said lever arm, and said fulcrum member during an adjustment in shut height of said press.

2. Apparatus as defined in claim 1 wherein said power piston rod includes a plurality of vertically arranged points of attachment for selective attachment thereto of said second end of said lever.

3. Apparatus as defined in claim 1 wherein said upright includes a plurality of vertically arranged points of attachment for selective attachment thereto of said fulcrum member.

4. Apparatus as defined in claim 1 wherein said power piston rod and said upright each includes a plurality of vertically arranged points of attachment for selective attachment thereto of said second end of said lever and said fulcrum member respectively.

5. In combination in a press having an adjustable shutheight, a frame having a first vertically arranged upright at one side thereof, a lower platen, an upper platen movable toward and from said lower platen, a second vertically arranged upright of said frame on the side of said platens opposite said first upright; means guiding said upper platen along at least one of said uprights during movement of said upper platen, a fulcrum member adjustably and removably mounted upon said first upright, a power piston-and-cylinder assembly pivotally mounted at the side of said frame opposite said first upright and having a power piston rod extending outwardly of said power cylinder, a lever extending across said upper platen and having a first end pivotally attached to said fulcrum member and a second end pivotally and removably attached to said power piston rod, a link pivotally attached at its respective ends to said upper platen and to said lever intermediate the ends of said lever, a lifting piston-and-cylinder assembly pivotally mounted on said frame above said upper platen and having a lifting cylinder means pivotally connecting said lifting piston rod to said upper platen, means for directing pressure fluid to and from said power piston-andcylinder assembly thereby to move said upper platen selectively toward and away from said lower platen and means for directing pressure fluid to and from said lifting piston-and-cylinder assembly thereby to support said upper platen, said lever arm, and said fulcrum member during an adjustment in shut height of said press.

6. Apparatus as defined in claim 5 wherein said means pivotally connecting said lifting piston rod to said upper platen includes said link.

7. Apparatus as defined in claim 5 wherein the attachment of said first end of said lever to said fulcrum lies between said uprights, and said attachment of said second end of said lever to said power piston rod lies outboard of said second upright, the distance between said fulcrum-lever attachment and lever-piston rod attachment being substantially greater than the distance between said fulcrum-lever attachment and lever-link attachment thereby to provide a substantial leverage action.

8. Apparatus as defined in claim 5 including a pair of brace members spaced from each other and rigidly mounted at the respective upper ends of said first and second uprights, said lifting piston-and-cylinder assembly being pivotally mounted between said brace members.

9. A press having an adjustable shut-height including a frame comprising a plurality of horizontally disposed parallel base plates spaced from each other, a first vertically arranged upright attached to each of said base plates adjacent the rearward end thereof, a second vertically arranged upright attached to each of the end-most base plates intermediate the ends of said end-most base plates, a lower platen supported upon the tops of said base plates between said first uprights and said second uprights, an upper platen movable toward and from said lower platen, means guiding said upper platen along at least one of said uprights during movement of said upper platen, a plurality of fulcrum members adjustably and removably mounted upon each of said first uprights, a plurality of power piston-and-cylinder assemblies pivotally mounted upon each of said base plates adjacent the forward end thereof and having a power piston rod extending outwardly of said power cylinder, a plurality of levers extending across said upper platen and each having a first end pivotally attached to one of said fulcrum members and a second end pivotally and removably attached to one of said power piston rods, a plurality of links each being pivotally attached at its respective ends to said upper platen and to one of said lever arms intermediate the ends of the lever arm, a pair of lifting piston-and-cylinder assemblies pivotally supported from the uprights of said frame respectively at the ends of said frame and each being mounted above said upper platen, each of said lifting assemblies having a lifting piston rod projecting downwardly, means pivotally connecting each of said lifting piston rods to the upper platen adjacent the ends of said upper platen, means for directing pressure fluid to and from each of said power piston-and-cylinder assemblies simultaneously thereby to move said upper platen selectively toward and away from said lower platen, and means for directing pressure fluid to and from each of said lifting piston-and-cylinder assemblies simultaneously thereby to actuate said upper platen, said lever arms and said fulcrum members during an adjustment in shut-height of said press.

10. A press as defined in claim 9 wherein the attachment of said second end of said lever to said power piston rod comprises a pin adapted for removal during adjustment from one shut height to another shut height of the press.

11. A press as defined in claim 9 wherein the attachment of said first end of said lever to said fulcrum member comprises a plurality of pins adapted for removal during adjustment from one shut height to another shut height of said press.

12. A press as defined in claim 9 wherein said means pivotally connecting the respective said lifting piston rods to said upper platen includes the respective links attached to said upper platen and to the end-most lever arms of said press.

13. In combination in a press having an adjustable shutheight, a frame having a vertically arranged upright at one side thereof, a lower platen, an upper platen movable toward and away from said lower platen while being maintained parallel thereto, a fulcrum member adjustably and removably mounted upon said upright, a power piston-and-cylinder assembly pivotally mounted at the side of said frame opposite said upright and having a power piston rod extending outwardly of said power cylinder, a lever extending across said upper platen and having a first end pivotally attached to said fulcrum member and a second end pivotally and removably attached to said power piston rod, a link pivotally attached at its respective ends to said upper platen and to said lever intermediate the ends of said lever, a pair of double-acting lifting piston-and-cylinder assemblies pivotally mounted upon said frame above said upper platen, each of said lifting assemblies having a piston rod projecting downwardly, means pivotally connecting each of said lifting piston rods to said upper platen, means for directing pressure fluid to and from said power pistonand-cylinder assembly thereby to move said upper platen selectively toward and away from said lower platen, means for directing pressure fluid to and from the respective ends of said double-acting lifting cylinders thereby to support said upper platen, said lever arm and said fulcrum member during an adjustment .in shut-height of said press, and means for simultaneously displacing fluid contained within said double-acting cylinders between the mutually non-corresponding ends thereof during movement of said upper platen by said power piston-andcylinder assembly thereby to permit said respective means connecting said lifting piston rods to said upper platen to move equal distances in unision and to assist in maintaining said upper platen parellel to said lower platen.

14. Apparatus as defined in claim 13 wherein said means for displacing fluid between the non-corresponding ends of said double-acting cylinders includes a valve controlled by-pass between the upper end of one of said lifting cylinders and the lower end of the other of said lifting cylinders, opening of said by-pass being adapted to balance the fluid supply in the corresponding ends of said lifting cylinders.

References Cited in the file of this patent UNITED STATES PATENTS 1,467,201 Shriver Sept. 4, 1923 1,945,879 Burger Feb. 6, 1934 2,356,790 Home Aug. 29, 1944 FOREIGN PATENTS 123,060 Austria May 26, 1931 

